Table 2.

Standardized regression coefficients (β), t-ratios, and p-values for each parameter, as well as R² for the full and final models from backwards elimination stepwise regression. Cp values for each step are provided for validation purposes.

Step	Parameter	□std β	t	p	Action	R2	Cp
1	Full model			0.15	Entered	0.15	6
2	Language Index	−0.014	−0.09	0.93	Removed		4.01
3	Immediate Memory Index	−0.046	−0.20	0.84	Removed		2.05
4	Attention Index	−0.059	−0.42	0.68	Removed		0.21
5	Visuospatial/Constructional Index	0.19	1.49	0.14	Removed		0.32
	Final model
	Delayed Memory Index	−0.33	−2.53	0.01		0.11

Dependent variable: One-week practice effect.

C_p = Mallow’s criterion, with smaller values indicated better model fit. Note that the values reported for each parameter are calculated after that parameter had been removed, e.g., C_p = 0.21 for Step 4 was calculated after the Attention Index score parameter was removed, leaving the Visuospatial/Constructional Index and Delayed Memory Index in the stepwise elimination.